"The Food and Drug Administration wants parents, caregivers and healthcare professionals to be aware that infants of any age may face an increased risk of developing a life-threatening condition if fed a thickening product called SimplyThick," according to an FDA release.

NEC, characterized by infection, inflammation, and destruction of tissue in the intestines, occurs mostly in premature infants. The exact cause is unknown.

While research is needed to affirm a link between SimplyThick and NEC, the FDA has issued the precautionary warning.

Thickening agents are mixed with breast milk and infant formula for premature babies who have trouble swallowing. It helps them keep food down without spitting up.

Upon first learning of health risks associated with SimplyThick in May 2011, the FDA issued a warning against feeding it to infants born prematurely. In a subsequent review of reports potentially linking health problems to SimplyThick, the FDA found that 22 infants had developed NEC after being fed SimplyThick. While 21 were born prematurely, one infant was born at full-term. As a result, the FDA has expanded its warning to all infants.

Symptoms of NEC, according to the FDA, include a bloated stomach, greenish-colored vomiting, and bloody stools.

SimplyThick is also used in older children and adults, but those patients are not included in the warning.

SimplyThick issued a recall in May 2011, "advising our customers and medical professionals to follow the FDA’s recommendation that SimplyThick brand thickener not be used with or given to babies who were born before 37 weeks." The company also issued a voluntary recall of its "thickening gel products manufactured at a food processing plant located in Stone Mountain, Georgia since June 1, 2009."